Electrical connector of the plug-and-jack type



Oct. 26, 1965 R. NEIDECKER 3,214,721.

ELECTRICAL CONNECTOR OF THE PLUG-AND-JACK TYPE Filed Aug. 50, 1962 2Sheets-Sheet 1 Fig.1

INVENTORI RUDOLF NE IDE QKE R Oct. 26, 1965 R. NEIDECKER 3,214,721

ELECTRICAL CONNECTOR OF THE PLUG-AND-JAGK TYPE Filed Aug. 50, 1962 2Sheets-Sheet 2 INVENTOR.

RUDOLF NE/DECMER BY jg,

AGENT United States Patent C 3,214,721 ELECTRICAL CONNECTOR OF THEPLUG-AND-JACK TYPE Rudolf Neidecker, Basel, Switzerland, assignor toMulti- Contact AG, Basel, Switzerland, a corporation of SwitzerlandFiled Aug. 30, 1962, Ser. No. 220,528 7 Claims. (Cl. 339-91) My presentinvention relates to an electrical connector consisting of a male memberor plug and a female member or jack releasably engageable with eachother.

At least one of the connector members, usually the jack, conventionallycomprises an array of resilient elongated conductors, hereinafterreferred to as contact springs, which elastically bear upon a conductiveportion of the other connector member when the two are interengaged. Itis evident that, in such an assembly, the current-carrying capacityincreases with the contact pressure between the two members whichreduces the transfer resistance along the area of interengagement andshould, therefore, be as great as possible. The extent to which thiscontact pressure can be increased is, however, limited by mechanicalconsiderations and also by the need for easy interconnection anddisengagement of the parts.

The general object of my invention is to provide means for selectivelyincreasing the contact pressure in such connector in the engagedposition of its members to enable its operation with a current-carryingcapacity approaching the rated capacity of each individual member. Arelated object is to provide means for preventing accidentaldisengagement of such members from each other.

These objects are realized, pursuant to a feature of the presentinvention, by the provision of an adjustable biasing element adapted tourge the contact springs of one member, preferably the jack, against aconductive surface of the other member Advantageously, the active member(eg the jack) has a generally cylindrical array of contact springsbearing concentrically upon a solid metallic portion of the passivemember (e.g. the plug). The biasing element may then comprise a flexiblestrap of limited elasticity, e.g. of textile fabric, leather, orthermoplastic material, which embraces a major part of thecontact-spring array and is tensionable by a suitable setting mechanismsuch as, for example, a manually rotatable crank shaft. Alternatively, alow-elasticity pressure block may be disposed between such crank shaftand a part of the array to place its contact springs under increasedstress. In either instance it will be desirable to select the shape ofthe setting element and/or the coeifcient of friction between the latterand the biasing element in such manner as to insure a self-locking ofthe assembly in stressed position.

The above and other objects, features and advantages of the presentinvention will become more fully apparent from the following detaileddescription of certain embodirnents, reference being made to theaccompanying drawi ing in which:

1 FIG. 1 is a side-elevational view of an assembled plugand-jackconnector according to the invention;

FIG. 2 is a cross-sectional view taken on the line 11-11 of FIG. 1;

FIG. 3 is a view similar to FIG. 1 tion thereof;

FIG. 4 is a cross-sectional view taken on the line IVIV of FIG. 3;

FIGS. 5 and 6 are further cross-sectional views, similar to FIGS. 2 and4, which illustrate additional modifications; and

FIG. 7 is a longitudinal sectional view taken on the line VIIVII of FIG.6 with the plug removed.

showing a modifica- The connector shown in FIGS. 1 and 2 comprises afemale member or jack 1 and a male member or plug 2 received therein.Jack 1 is generally in the shape of a cylindrical sleeve with twoperipherally projecting lugs 16 axially spaced from each other and witha peripheral gap 17 between these lugs. The plug 2 is also ofcylindrical configuration and, as here shown, may be a solid metallicrod; one of its extremities is conductively connected in conventionalmanner not further illustrated, to a flexible cable 3 while a similarcable 4 is connected to the conductive portion of jack 1 represented bya tubular array of contact springs 5. The springs 5 extend axiallywithin the preferably non-conductive housing portion of jack 1 to whichthey are anchored on opposite sides of the gap 17; they may be slightlybent inwardly, i.e. toward the common axis of members 1 and 2, so as tobear with moderate pressure upon the surface of plug 2 when the latteris inserted into the jack 1.

A flexible strap 7 surrounds the major part of the array of contactsprings 5 and also embraces the olfset portion of a crank shaft 8 whichis journaled in the lugs 16 and may be manually rotated with the aid of,for example, a suitable key (not shown) insertable into a polygonalsocket 6 thereof. In its illustrated position the crank shaft 8 leavesthe strap 7 relatively slack so that the contact springs 5 engage theplug 2 only or mainly under their inherent stress of deformation; whenthe shaft is rotated through into an operative position in which it isretained by its frictional engagement with the strap 7, the latter istensioned so as materially to increase the pressure exerted upon theplug 2 by most of the contact springs 5. The sector 14 of the arrayrepresents a region within which the upward tension of strap 7 isopposed by the downward reaction of the spring mounting within thehousing portion of jack 1; arrows 13 denote the op posing forces as thesprings in that sector are initially spread apart upon insertion of theplug 2 and are further deflected upwardly by the operation of crankshaft 8. As will be seen in FIG. 2, the spacing of the spring arrayforming a housing wall of the jack corresponds to substantially thewidth of strap 7.

FIGS. 3 and 4 show a connector whose jack 1a is a metallic tube that hasbeen longitudinally slitted along an intermediate portion to formcontact springs SaandSa". Rings 16a, preferably of insulating material,surround the unslitted extremities of the tube and are formed witharcuate recesses 15 in which a crank shaft 8a is cradled; this shaft hasa polygonal head 6a engageable by a key or wrench for the purpose ofmanual operation. Strap 7a embraces the shaft 8a and the major part ofthe spring array 5a, So": it will be noted that the narrower, moreeasily deflected contact springs 5a are distributed over a sectoropposite the shaft 8a, the reaction force being provided by the widersprings 5a". Strap 7a, in addition to providing a biasing force for thecontact springs, also serves as a means for holding the shaft 8a inposition.

The connector shown in FIG. 5 comprises a jack 1b and a plug 2bgenerally similar to those of FIGS. 1 and 2. Crank shaft 8b, journalledin a pair of lugs 16b on the jack housing, traverses a pressure block912 (e.g. of polystyrene) which acts upon the upper contact springs 5bof the array surrounding the plug 211. The reaction sector has beendesignated 14b, the arrows 13b again indicating the displacement of thecontact springs Within that sector.

FIGS. 6 and 7 illustrate the manner in which a convenentional jack 1ccan be adapted for use with a biasing element according to theinvention. For this purpose the tubular jack housing is cut away at 10so as to expose a minor segment of the array of contact spring 50surrounding the plug 20. A strap 70, which may be (a molded from plasticmaterial such as polystyrene, embraces the jack 1c in the region of gap10 and coaxially surrounds the array of springs c, the clearance betweenthis array and the lower part of strap 70 being occupied by a spacerblock 11 which is held onto the strap by means of pins 12. Crank shaft8c, provided with a socket 6c, bears with its concentric extremitiesdirectly upon the jack 1c in which it is held in position solely by thestrap 70. The arrows of the opposing forces and the sector of theirinteraction have been indicated in FIG. 6 at 13c and 140, respectively.

As will be apparent from the foregoing description, the herein disclosedmeans for additionally biasing the contact springs of a connector memberoperate in each instance to reduce the contact resistance of theconnector, thereby increasing its current-carrying capacity, and toprevent inadvertent or spontaneous separation of its parts. Departuresfrom the specific arrangements described and illustrated are, of course,possible within the spirit and scope of the invention as defined in theappended claims.

I claim:

1. A connector for electrically linking a pair of conductors, saidconnector comprising a female member having a longitudinal bore, agenerally cylindrical male member secured to a first one of saidconductors and receivable in said bore, said female member including atubular array of contact springs disposed about the periphery of saidmale member and connected to the sec ond one of said conductors, saidcontact springs being engageable with a conductive surface portion ofsaid male member, setting means including a crankshaft rotatablysupported on said female member on one side of said bore, andselectively actuable and generally radially shiftable biasing meansoperatively connected with said crankshaft, said biasing means having alongitudinally extending surface diametrically opposite said crankshaftand coaxial with said bore while being juxtaposed and engageable with atleast a segment of said array dia metrically opposite said crankshaftwith respect to said bore for urging said contact springs against saidsurface portion of the male member.

2. A connector for electrically linking a pair of conductors, saidconnector comprising a female member having a longitudinal bore, agenerally cylindrical male member secured to a first one of saidconductors and receivable in said bore, said female member including atubular array of contact springs disposed about the periphery of saidmale member and connected to the second one of said conductors, saidcontact springs being engageable with a conductive surface portion ofsaid male member, setting means including a crankshaft rotatablysupported on said female member, and selectively actuable biasing meansoperatively connected with said crankshaft and engageable with at leasta segment of said array for urging said contact springs against saidsurface portion of the male member, said biasing means comprising atensionable strap embracing said array and said crankshaft.

3. A connector according to claim 2 wherein said female member comprisesa metallic tube provided with longitudinal slit-s whereby said contactsprings are formed as integral parts of said tube.

4. A connector according to claim 3 wherein said slits are more numerousat a segment of said tube remote from said setting means.

5. A connector according to claim 2 wherein said female member comprisesa tubular housing supporting said array, said housing having aperipheral gap exposing said array at a location remote from saidsetting means for admitting said strap into contact with said array.

6. A connector according to claim 5, further comprising a spacing blockinserted in said gap between said strap and said array.

7. A connector according to claim 1 wherein said biasing means comprisesa pressure block bearing laterally upon said array and said crankshaftis journaled in said female member in contact with said block for urgingthe same toward said array.

References Cited by the Examiner UNITED STATES PATENTS 1,667,485 4/28MacDonald 339273 X 1,673,738 6/28 Dibner 3394268 X 1,876,663 9/32 Graveset al 33925l X 2,056,248 10/36 Buchanan 339-268 2,410,961 11/46 Carson339274 2,681,441 6/54 Linn 339262 2,685,075 7/54 M01 339251 2,952,0029/60 Angele et al. 339- FOREIGN PATENTS 898,732 7/44 France.

16,854 5/00 Great Britain.

JOSEPH D. SEERS, Primary Examiner.

1. A CONNECTOR FOR ELECTRICALLY LINKING A PAIR OF CONDUCTORS, SAIDCONNECTOR COMPRISING A FEMALE MEMBER HAVING A LONGITUDINAL BORE, AGENERALLY CYLINDRICAL MALE MEMBER SECURED TO A FIRST ONE OF SAIDCONDUCTORS AND RECEIVABLE IN SAID BORE, SAID FEMALE MEMBER INCLUDING ATUBULAR ARRAY OF CONTACT SPRINGS DISPOSED ABOUT THE PERIPHERY OF SAIDMALE MEMBER AND CONNECTED TO THE SECOND ONE OF SAID CONDUCTORS, SAIDCONTACT SPRINGS BEING ENGAGEABLE WITH A CONDUCTIVE SURFACE PORTION OFSAID MALE MEMBER, SETTING MEANS INCLUDING A CRANKSHAFT ROTATABLYSUPPORTED ON SAID FEMALE MEMBER ON ONE SIDE OF SASID BORE, ANDSELECTIVELY ACTUABLE AND GENERALLY RADIALLY